Acrylonitrile monomer is a basic building block for a number of very important polymers. By polymerizing acrylonitrile polyacrylonitrile may be obtained. It is a white fiber that has a very good resistance to acids, common solvents, oils, greases, salts, and sunlight. Nitrile rubbers which have excellent abrasion, oil and chemical resistance are prepared by the copolymerization of butadiene and acrylonitrile. Acrylonitrile monomer can be utilized in a great many other copolymers and terpolymers.
After the synthesis of a polymer that contains linkages that are derived from acrylonitrile is completed, some unpolymerized acrylonitrile monomer will still be present. Polymers that contain acrylonitrile linkages, acrylonitrile polymers, are normally synthesized by emulsion polymerization in an aqueous system. The unpolymerized residual acrylonitrile normally remains in both the acrylonitrile polymer itself and in the water. The normal procedure of stripping by vacuum or steam does not usually remove all of this undesirable residual acrylonitrile. Since acrylonitrile is believed to be toxic, it would be highly desirable to remove substantially all free residual acrylonitrile.